The invention relates generally to a weatherstrip for a motor vehicle and more specifically to a two piece outer belt weatherstrip for disposition between the window and door of a motor vehicle.
Most motor vehicles are equipped with movable window glass that slides in a window opening from an up or extended position that seals off the opening to a down position, retracted within the vehicle body, that opens all or a portion of the window opening and allows an exchange of air between the inside and outside of the vehicle. A sealing device generically referred to as a weatherstrip is disposed about the periphery of the window opening and provides an air and watertight seal between the vehicle body and the window glass. The interface between the body and the movable window glass at the lower margin of the window opening is typically equipped with a weatherstrip denominated a beltstrip which aesthetically hides the interface and provides at least one wiper flange or blade for cleaning the window as the window extends from and retracts into the body of the vehicle.
Design and engineering effort directed to vehicle streamlining for drag reduction and reduction of wind noise is ongoing. To achieve these goals, design considerations such as the elimination of all gaps and channels, low profile configurations, overlapping of the beltstrip or weatherstrip on the glass, as well as installation ease, serviceability and durability have received significant attention. The challenge of achieving such goals depends upon the proper execution of such design considerations.
Beltstrips and weatherstrips are generally extruded or roll-formed in a complicated manufacturing process having many steps. Typically, a core metal structure is formed and coated with an adhesive to bond a subsequently extruded layer of synthetic elastomeric material to the metal to form a belt molding which is then cut to length. A sealing strip having a flexible blade for contacting the window may be formed and coated in an extrusion process utilizing rubber or a similar material. An inner surface of the blade is generally flocked to provide a low friction coating exhibiting reduced sliding friction between the blade and the window glass and to reduce the tendency of the weatherstrip and window glass to squeak. The sealing strip is typically affixed to the belt molding. The belt molding and the sealing strip are notched at spaced locations. Clips are then inserted into the notches to couple the belt molding and the sealing strip. The clips also grip a flange formed on the door of the vehicle to hold the weatherstrip to the door.
The materials used to form the weatherstrip are typically a combination of thermoset elastomer or thermoset and thermoplastic elastomer. For example, an elastomer may be extruded over a metal carrier and then a post assembled laminate strip of cosmetic film and metal that is roll formed into a C-configuration is mechanically fastened over a section of the front surface of the belt weatherstrip.
The requirement of cosmetic surfaces dictates that the surface area be made of a specific thermoplastic, a decorative film or consist of a painted metal while providing a seal to prevent air and water leakage. Conventional weatherstrips lack the flexibility to interchange the front surface in order to provide a different cosmetic appearance.